Java 在junit中模拟方法中的变量

如果我正在为以下方法编写Junit，如何模拟clientInstance.execute

public class ClassName{
    public static <type> fun(){
        HttpClient clientInstance = null;
        // clientInstance initialised here 

        response = clientInstance.execute();
        //I am trying to mock clientInstance.execute 
    }
}

公共类类名{
公众娱乐{
HttpClient-clientInstance=null；
//clientInstance在此处初始化
response=clientInstance.execute（）；
//我试图模拟clientInstance.execute
}
}

您可以使用

Mockito.mock为clientInstance创建一个mock实例，然后使用
Mockito定义它返回的内容。当
时，如下所示：

HttpClient clientInstance = Mockito.mock(HttpClient.class); // initialize mock
Object mockReturn = new Object(); // define your return object
Mockito.when(clientInstance.execute()).thenReturn(mockReturn); // define what mock returns
Object response = clientInstance.execute(); // call your mock

如前所述，您最好重新设计代码以实现可测试性：

public class ClassName {
    public static <type> fun(HttpClient clientInstance){
        response = clientInstance.execute();
        //I am trying to mock response.execute 
    }
}

如果HttpClient
初始化很棘手，您想测试它，该怎么办？您可以将其重构为另一种方法：

public class ClassName {
    /**
      * Package-private for testing reasons.
      * Do not call it from within the class in production code!
    */
    static HttpClient createHttpClient() {
        HttpClient clientInstance = null;
        // clientInstance initialised here 
        return clientInstance;
    }

    /* this method is *not* going to be tested */
    public static <type> fun(HttpClient clientInstance){
        HttpClient clientInstance = createHttpClient();
        return fun(clientInstance);
    }

    /* this method is going to be tested */
    public static <type> fun(HttpClient clientInstance){
        response = clientInstance.execute();
        // mocking clientInstance.execute() will be easy now
    }
}

公共类类名{
/**
*出于测试原因，包是私有的。
*不要在生产代码中从类内部调用它！
*/
静态HttpClient createHttpClient（）{
HttpClient-clientInstance=null；
//clientInstance在此处初始化
返回客户端实例；
}
/*此方法*不*将被测试*/
公共静态乐趣（HttpClient客户端实例）{
HttpClient clientInstance=createHttpClient（）；
返回乐趣（clientInstance）；
}
/*这一方法将得到检验*/
公共静态乐趣（HttpClient客户端实例）{
response=clientInstance.execute（）；
//模仿clientInstance.execute（）现在很容易了
}
}

如果其他所有操作都失败，您可以使用模拟构造函数。我从未见过值得费心的案子。无论如何，解释了如何使用它。
您不能。您需要将clientInstance注入
fun（）
方法或使其成为一个实例变量。因此，除了修改上述函数之外，没有办法模拟clientInstance.execute（）。当（（Mockito.any（HttpClient.class.execute（））。然后返回（httpResponse）
它会工作吗？遗憾的是，问题没有解决“如何使用Mockito？”或“如何修改代码使其可测试？”。
public class ClassName {
    /**
      * Package-private for testing reasons.
      * Do not call it from within the class in production code!
    */
    static HttpClient createHttpClient() {
        HttpClient clientInstance = null;
        // clientInstance initialised here 
        return clientInstance;
    }

    /* this method is *not* going to be tested */
    public static <type> fun(HttpClient clientInstance){
        HttpClient clientInstance = createHttpClient();
        return fun(clientInstance);
    }

    /* this method is going to be tested */
    public static <type> fun(HttpClient clientInstance){
        response = clientInstance.execute();
        // mocking clientInstance.execute() will be easy now
    }
}